1. Field of the Invention
The present invention relates to a planar light source device and a display device.
2. Description of the Related Art
In the past, there is a known planar light source device, as shown in JP-A No. 2007-206398. This planar light source device has an object of lightning the effect of a luminance decrease in accordance with the boundary of light guide blocks on a light diffusion plate of a display device.
As disclosed in JP-A No. 2005-17324 and JP-A No. 1999-109317, according to a known technique, a display screen is divided into a plurality of blocks, the backlight luminance is changed in the unit of divided blocks in accordance with an input image signal. JP-A No. 2005-17324 and JP-A No. 1999-109317 suggest for low consumption power and for expanding the dynamic range of a display luminance, by changing the backlight luminance in accordance with an input image signal.